This spring we celebrated the 50th anniversary of the “Diatom Clinic”, which was started by then graduate student Gene Stoermer at the Iowa Lakeside Laboratory in 1963. Our class of 10 students arrived from all over the country (Alaska, Arizona, Arkansas, California, Colorado, Louisiana, Maryland, Minnesota, Ohio), and with varying backgrounds (undergraduates, recent graduates, graduate students, professors, professionals) to explore and learn about the world of diatoms. Mark Edlund and Marina Potapova led the charge during this extraordinary and enlightening four-week stay on the shores of West Lake Okoboji.

Dr. Evelyn Gaiser from Florida International University visited Lakeside Lab during the class and gave several lectures and a public talk entitled "From Poutine to Boiled Peanuts:  Unraveling the Biogeography of Karstic Wetland Diatoms from Canada to the Tropics". Evelyn is an alumnus of the 1989 Diatom Class, the last class taught by Dr. Charlie Reimer, and did her M.S. research at Lakeside on epizooic diatoms of the Iowa Great Lakes region.

In addition to a rigorous workload, this year’s class took on an exciting project examining a population of Diatoma vulgaris from East Lake Okoboji that had recently undergone sexual reproduction. Shallow epilithic samples collected from East Lake Okoboji, Dickinson County, Iowa had highly variable populations of Diatoma including Diatoma vulgaris and its varieties, linearis and breve. A bi-modal distribution of valve lengths was observed for the Diatoma varieties ranging from 21 to 88 µm. Initially the length distribution was dominated by an abundance of valves between 60-70 µm and a smaller population with lengths between 30-40 µm. After three weeks the populations were resampled and the bi-modal distribution shifted to dominance by the 30-40 µm valve length group. Across the length range valves showed little variation in breadth and costae density, so we further examined the morphology using sliding landmarks to describe valve shape. Multivariate analysis of the sliding landmarks yielded a morphological trajectory axis where valves with a narrow middle and long capitate ends were reduced to valves with a central widening and rounded subrostrate ends. When valve shapes along this axis were compared with valve diminution, a decrease in valve length explained 93% of the variation in the change from a narrow middle with capitate ends to the central widening and rounded ends. These data indicate that our collections represent a single taxon, which we determine to be Diatoma vulgaris, that the population had recently undergone sexual reproduction, and that within the size and shape variation of this single species many of its described varieties can be accommodated.

David Burge and Natalie Hoidal will be giving an oral presentation of the class project at the 2013 North American Diatom Symposium in Maine this August.


  • J.C. Kingston Fellowship

    Teaching Fellowship - David R.L. Burge

  • C.W. Reimer Scholarship

    Merit Scholarship - Dawn DeColibus

  • Friends of Lakeside Lab

    Educational Support

  • Okoboji Foundation

    Educational Support

  • Roy J. Carver Charitable Trust

    Student Microscopes and Imaging

  • Messengers of Healing Winds

    Student Microscopes and Imaging


Mark Edlund

Content Editor, Centric Diatoms Diatoms of North America, Editoral Review Board

Senior Scientist Science Museum of Minnesota

Marina Potapova

Content Editor, Monoraphid Diatoms Diatoms of North America, Editoral Review Board

Curator Diatom Herbarium, Academy of Natural Sciences of Philadelphia, Drexel University

David R.L. Burge

Content Editor, Araphid and Centric Diatoms Diatoms of North America, Editoral Review Board

Assistant Scientist St. Croix Watershed Research Station

Phytoplankton Scientist Natural Resources Research Institute

Steve Main

Professor emeritus Retired, Wartburg College

Ian Bishop

Content Editor, Araphid Diatoms Diatoms of North America, Editoral Review Board

Graduate Student Graduate School of Oceanography, University of Rhode Island

Dan Bogan

Aquatic Ecology Research Professional Alaska Natural Heritage Program, University of Alaska Anchorage

Dawn DeColibus

M.S. Student Ball State University

Natalie Hoidal

Undergraduate Student University of Minnesota, Morris

Justin Kenneth Jones

M.S. Student Towson University

Marge Penton

Diatom Enthusiast Rocky Mountain Biological Lab

Aneliya Sakaeva

M.S. Student University of Colorado, Boulder

Thomas C. Smith

Ph.D. Student University of California, Santa Barbara, Dept. of Ecology, Evolution, and Marine Biology

Dessie Underwood

Professor California State University Long Beach

Shelly Wu

Diatom Enthusiast

Evelyn Gaiser

Florida International University

Peter Van der Linden

Director, Iowa Lakeside Lab

Jane Shuttleworth

Friends of Lakeside Lab

Natalie Bymark
Image Credit: Mark Edlund
Natalie Hoidal sampling for diatoms.
Diatoma Jessie
Image Credit: Dessie Underwood
Students examined the size distribution of Diatoma as a class project. The results are presented at the 2013 North American Diatom Symposium.
Sem Wartburg
Image Credit: Dawn DeColibus
Loading scanning electron microscope stubs in the stage, Wartburg College SEM Laboratory.
Image Credit: Dawn DeColibus
Shelly Wu and Rick Otto walk gently in the Miocene sands at Ashfall Fossil Bed, Nebraska.
Shelly Wu, Natalie Hoidal and Dawn DeColibus in Dead Man's Bog, Iowa.
Aneliya Sakaeva and Mark Edlund scrutinize the sediment/water interface in a sediment core from East Lake Okoboji.
Markclass Bytome
Image Credit: Thomas Smith
Mark Edlund and class exploring the spring off the "north 40" from Iowa Lakeside Lab.